<!DOCTYPE html>
<meta charset="utf-8">
<title></title>
<style>
html, body {
    margin: 0;
    padding: 0;
}
main {
    height: 300px;
    width: 250px;
    background-image: linear-gradient(to bottom, red, blue);
    background: blue;
    position: absolute;
    top: 0;
    left: 0;
}

div {
    position: absolute;
    top: 200px;
    left: 0;
    height: 100px;
    width: 200px;
    background: green;
}

</style>
<main><div></div></main>


